Burring tool



June 20, 1944. BAUER 2,351,578

BURRING TOOL Filed March 15, 1945 INVENTOF Q Patented June 20, 1944 BURRING TOOL Arthur G. Bauer, Hempstead, N. Y., assignor to South Shore Machine & Tool Works, Inc., Seaford, N. Y.-, a corporation of New York Application March 18, 1943, Serial No. 479,661

2. Claims.

The present invention relates to improvements in burring tools, the principalobject of the invention being to :provide a simple and effective tool for removing burrs at points which are not readily accessible to toolsof standard design.

It is well known that drilling operations on metal, particularly the relatively soft metals, result in the formation of a burr around the drilled hole, that is, irregular projections of metal will be found at the edges of the drilled hole on the side from which the drill enters but more particularly on the side from which the drill emerges. It is generally necessary to remove this burr and in many instances the burr is not accessible to ordinary burring tools. Such a situation is encountered in the production of a yoke, which may be referred to by way of illustration, wherein holes must be drilled, usually in one operation, through both arms of the yoke to receive a pin for holding a male member in place. It is a simple operation to remove burrs from the outer surfaces of the yoke, but it is diflicult to bring any ordinary tool to bear upon the inner surfaces. The tool of the present invention has been developed for use under such circumstances and in other situations where similar conditions exist.

Referring to the accompanying drawing which shows a preferred embodiment of the invention selected for purposes of illustration,

Figure 1 is a side elevation of a tool embodying the invention with its associated driving spindle and a typical work piece from which burrs are to be removed;

Figures 2 and 3 are top plan views of the illustrative tool and handle, before assembly;

Figures 4 and 5 are longitudinal sections of the tool and handle, before assembly;

Figure 6 is a plan view of the under side of the tool and handle in assembled relation to each other; and

Figures 7 and 8 are respectively a vertical section and side elevation of a modified form of tool.

Referring to the drawing, a conically faced burring tool I is mounted for rotation in a handle 2. The burring tool may be of hardened steel or other suitable material provided with sharp cutting edges like a rose bit countersink as shown in Figures 1 and 6, or it may be provided with an abrasive cutting surface as shown in Figures '7 and 8. The angular disposition of the cutting face to the axis of rotation of the tool may be selected as desired, but it is important that the length of the tool along its axis be relatively short as compared to its overall diameter. Preferably the handle2 is relatively thin and flat and is arranged in a plane at right angles to the axis of rotation of the cutting head: i.

As shown in Figurelthecutting head I is adapted to be rotated by a spindle 3 which is provided at its lower end with means to engage the head, herein shown as a taperedsquared portion adapted to enter a matching socket in the head as will appear more clearly from Figure 4. Preferably the tapered end and socket, or other means of engagement, are so related that the two parts may be readily engaged and disengaged. The driving spindle 3 may be chucked in a drill press, if the work piece is small or easily positioned therein, or in a portable hand or power driven chuck, if the work piece is not readily portable.

Figure 1 also shows a typical yoke through the arms of which holes 5 and 6 have been drilled leaving burrs surrounding the drilled holes as shown. Assuming that the driving spindle is chucked in a drill press, the yoke 4 and the tool I may be brought into the relative positions shown, or more conveniently with the cutting face of the tool partially entering the hole 6. Then the two may be placed under the spindle 3, which may be rotating at a suitable speed, and moved upwardly until the spindle passes through the hole 5 and its end engages the socket in the cutting head. This will cause the cutter to rotate and further upward movement of the yoke will bring about the necessary cutting pressure of the tool upon the work.

If desired the work piece may be fixed in the drill press so that the holes 5 and 6 are aligned with the spindle 3 and then the tool may be placed as shown and the spindle lowered in the usual manner.

Thus one of the burrs will be removed and the edge of the hole 6 beveled more-or less as desired, the angle of the bevel conforming to the selected angular relation of the cutting face of the tool to its axis of rotation. This angular relation may be or less as desired.

Similarly the burr on the underside of the hole 5 may be removed by reversing the position of the yoke 4. The tool may also be used to remove the burrs from the outer surface of the yoke arms although this operation can be accomplished with standard tools.

Figures 2 to 6 illustrate a preferred construction of tool and holder which enables them to be readily assembled. As clearly shown in Figure 4 the cutting head I is provided with an annular groove 9, the diameter of the head at the bottom of the groove being slightly less than the distance between prongs 1 and 8 of the holder or handle 2 as shown in Figure 3. The cutting head may be easily assembled with the holder by placing it in the opening between the prongs I and 8 and bending them toward each other as indicated in Figure 6. Thus the prongs 'l and 8.wil1 engage the groove 9 and permit rotation of the cutting head in the holder. '1

It will, ofcourse, be understood that the burring tool herein described may be made in several sizes in order that an appropriately sized cutter will be available for use upon different sized yokes, or the like, and upon the same size of yoke with holes of different diameters. In eachsinstance the dimensions of the cutting heads will be held to a minimum in the direction'of. their axes of rotation and the working face made relatively large in order that the tool may be used on work pieces having drilled holes of various diameters.

In the modified form shown in Figures 7 and 8 the cuttinghead consists of two parts Ill and II, the former of steel provided with'a socket and groove to be engaged respectively by the driving spindle and handle, and the latter an abrasive element which is cemented or otherwise attached. It will also be understood that the invention herein described may be variously embodied within the scope of the subjoined claims.

I claim as my invention:

1. A burring tool comprising, in combination, a cutting head provided with an angularly disposed cutting face, an annular groove disposed above said cutting face, a socket in said: cutting head for engagement with a rotatable spindle, and a handle disposed at substantially .rightangles to the axis of rotation of the cutting head, said handle being mounted in said annular groove and said cutting head being freely rotatable in said handle.

2. A burring tool comprising, in combination, a

shankless cutting head having aconical working ennui? ,G Q iBAUER. 

